Atmospheric New Particle Formation and Climate Sensitivity: the CLOUD experiment 4th April 2017 Molteni Ugo ugo.molteni@psi.ch
About me Master degree in Applied and Environmental Chemistry at the University of Milan PhD student at the Laboratory of Atmospheric Chemistry, Energy and Environment Research Division at the Paul Scherrer Institute https://www.psi.ch/lac/ Working at the CERN CLOUD (Cosmics Leaving OUtdoor Droplets) experiment
Outlook Aerosol and the impact on visibility, health and climate New particle formation in troposphere The CERN CLOUD experiment and recent results Field results an the High Altitude Jungfraujoch Research Stations
Atmosphere www.noaa.org
Atmospheric New Particle Formation and Climate Sensitivity: the CLOUD experiment Aerosol is defined as a suspension of fine solid or liquid particles in a gas: Dust, Fog, Fume, Hazes, Mists, Particles, Smog, Smoke, Soot We will focus on the dispersed phase Few hundred to few thousand particles per cc Diameter: few nm few μm
Atmospheric Science - History Ancient Greeks thought that emissions from their cooking activities were reaching the mount Olympus ad feeding gods. The Great Smog of 1952, London Photochemical Smog, LA basin 70 Ozone hole - 1995 Nobel Prize in Chemistry
Aerosol Sources Biogenic Anthropogenic Primary Secondary Ozone, OH, NO3 Oxidation processes www.bnl.gov
Aerosol global distribution Dust (red), sea salt (blue), organic/black carbon (green), and sulfates (white) https://svs.gsfc.nasa.gov
Why do we study aerosol? Visibility Health Climate
Visibility Seinfeld and Pandis, 1998 1)Residual light from the target reaching the observer 2)Light from the target scattered out of the observer s line 3)Light scattered into the observer s line 4)Background scattered light
Visibility Shanghai
Health asthma, lung cancer, heart disease, cognitive aging, Alzheimer s disease and other forms of dementia. Emily Underwood, Science Magazine
Aerosol and Climate IPCC (Intergovernmental Panel on Climate Change) Fifth Assessment Report: The Physical Science Basis Clouds and Aerosols Impacts, Adaptation, and Vulnerability Mitigation of Climate Change
Radiative Forcing greenhouse gases - CO2 Svante Arrhenius 1896, first evidence of the link between CO2 and greenhouse effect IPCC, 2013: Summary for Policymakers. In: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change
Climate Sensitivity Radiative Forcing IPCC, 2013: Summary for Policymakers. In: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change
Radiative Forcing - Aerosol IPCC, 2013 Climate Change 2013: The Physical Science Basis.
Radiative Forcing - Aerosol IPCC, 2013 Climate Change 2013: The Physical Science Basis.
Particles act as cloud condensation nuclei. Globally half of them are primary emitted, half are formed in the atmosphere Merikanto et al., 2009
Nucleation or new particle formation http://cloud.web.cern.ch/
The CLOUD (Cosmics Leaving OUtdoor Droplets) experiment at CERN
The CERN CLOUD experiment Which chemical species are involved new particle formation? Do galactic cosmic rays play a role in new particle formation?
Galactic cosmic ray
Ion induce new particle formation Kirkby, 2008
Kirkby, 2008
CERN facility CLOUD is here! http://cern.ch
East Hall CLOUD uses the T11 3.5 GeV/c secondary π+ beam http://cern.ch
The CLOUD chamber is a 3 m diameter electro-polished stainless 3 steel cylinder of 26.1 m
T11 End of the beam line Kirkby, 2008
East Hall - T11 http://cloud.web.cern.ch/
The Chamber Kirkby et al., 2011
Beam Shutter http://cloud.web.cern.ch/
Instrumentation Physics Chemistry Particle number Precursors Size distribution Cluster composition Ion distribution Particle composition Kirkby et al., 2016 Junninen et al., 2010
New particle formation Binary nucleation SO2 + OH HOSO2 HOSO2 + O2 SO3 + HO2 SO3 + H2O H2SO4 Clusters (H2SO4)m(H2O)x Kirkby et al., Nature (2011) Ternary nucleation Clusters: (H2SO4)m(NH3)n(H2O)x (H2SO4)m(DMA3)n(H2O)x Almeida et al., Nature (2013)
Oxidation Products of Biogenic Emissions Contribute to Nucleation of Atmospheric Particles SO2 OH radical H2SO4 OH radical BioOxOrg Riccobono et al., Science (2014) Schobesberger et al., PNAS (2013)
New particle formation in preindustrial, pristine environment: pure biogenic nucleation
The Autoxidation mechanism Kroll et al., 2011 Crounse et al., 2013 Ehn et al., 2013
Pure biogenic new particle formation Volatile organic compounds 2.4 Pg/y of reactive carbon 90% Biogenic: 44% isoprene 11% terpenes 10% Anthropogenic Sindelarova et al., (2014) Kirkby et al., Nature (2016)
Kirkby et al., Nature (2016)
Pure biogenic new particle formation Kirkby et al, Nature (2016)
The role of low-volatility organic compounds in initial particle growth in the atmosphere Tröstl et al., Nature (2016)
Bianchi et al., Science (2016)
Conclusion Climate change is linked to climate sensitivity: a temperature change in response to radiative forcing We well know the temperature increased from 1750 and we well know greenhouse gases concentration from ice cores but we have large uncertainty on aerosol load CLOUD in the past 5 years of operation identified precursors of new particle formation CLOUD answers 2 big questions: how cloudy was the pre-industrial climate and how much clouds have changed due to human activities Pure biogenic nucleation was the process in pristine environment CLOUD knowledge will help reduce uncertainty in climate projections
Thanks for your attention More at http://cloud.web.cern.ch/ ugo.molteni@psi.ch